Method for passive keyless entry of a motor vehicle especially of an industrial vehicle

ABSTRACT

A vehicle unlocking sequence includes passively authenticating a vehicle user, granting the authenticated vehicle user access to the vehicle and setting the vehicle main switch into an on-state. A vehicle locking sequence includes passively authenticating the vehicle user, configuring the vehicle, upon a first action from the authenticated vehicle user, into a first locking mode whereby access to the vehicle is denied to a non authenticated user, or configuring the vehicle, upon a second action from the authenticated vehicle user, into a second locking mode whereby access to the vehicle is denied to a non authenticated user and the vehicle main switch is set into an off-state.

BACKGROUND AND SUMMARY

The present invention concerns a method for passive keyless entry of amotor vehicle especially of an industrial vehicle.

In the recent years, some motor vehicles have been equipped with passivekeyless entry systems which make it possible to gain entry to a vehiclewithout requiring any action from a vehicle user.

Typically, a passive keyless entry system includes a two way radiocommunication between a vehicle and an electronic key which is carriedby the vehicle user. A passive keyless entry system may employ one ormore antennas fitted in the vehicle. The antennas are capable ofdetecting the presence of the electronic key within an operative area ofa few metres.

The system can be designed to give vehicle access, usually by unlockingone or more vehicle door(s), when the electronic key is within theoperative range of the antennas. Access to the vehicle is given after anauthentication of the electronic key.

Alternatively, to avoid a constant monitoring of the presence of theelectronic key and, thus consuming electric power, the system can bedesigned to wait for a trigger which conveniently is the user's actionto lift a door handle. This trigger is the event which the system usesto query the electronic key and determine whether or not to grantvehicle access to the user.

An industrial vehicle such as a truck may benefit greatly from a passivekeyless entry system in term of user comfort.

One of the many specific features of an industrial vehicle is thepresence of main switch or isolation switch. A main switch is an on-offswitch that controls the current from the battery storage. The mainswitch can be located on the battery box or on the vehicle cabin floor.The function of the main switch is to isolate the battery from thevehicle electrical circuit. This proves useful to spare battery electricpower when a vehicle is at a standstill for a long period of time. Thisalso proves useful during the loading operation of a potentiallyexplosive cargo whereby any electric arc has to be avoided.

In light of the above technological background, it is desirable toprovide a passive keyless entry system for an industrial vehicle. Anaspect of the invention concerns a keyless entry and exit method for avehicle which includes a vehicle main switch. The method comprises (i) avehicle unlocking sequence. This sequence comprises the steps ofpassively authenticating the vehicle user, granting the authenticatedvehicle user access and turning the vehicle main switch into an onstate. The method further comprises (ii) a vehicle locking sequence.This sequence comprises the steps of passively authenticating thevehicle user, and configuring the vehicle, upon a first action from theauthenticated vehicle user, into a first locking mode whereby access tothe vehicle is denied to a non authenticated user, or configuring thevehicle, upon a second action from the authenticated vehicle user, intoa second locking mode whereby access to the vehicle is denied to a nonauthenticated user and the vehicle main state is turned into an offstate.

An aspect of the invention, therefore, offers a method which takes intoaccount a specific feature of an industrial vehicle. An important aspectof an aspect of the invention is that the command of a vehicle mainswitch which is a common feature of industrial vehicles is integrated ina passive keyless method to unlock and lock a vehicle. An aspect of theinvention provides a passive entry and exit method of an industrialvehicle and integrates the control of the vehicle main switch. The termpassive is to be understood from a user point of view; in the presentinvention, the term passive means that no authentication input is to berequired from the user as opposed to, for example, a traditional keybased system where the user has to find the key and enter said key intoa keyhole or as opposed to a remote keyless system where the user has tofind a transmitter and, then, has to press a button on said transmitter.With the present invention, the user is passively authenticated and canthen configure the vehicle in an appropriate locking mode.

In a preferred embodiment of an aspect of the invention, the userauthentication can be based on bidirectional communication between aportable identification unit and an onboard control unit which isconnected to vehicle locking means and to the vehicle main switch.

It is envisaged that the first locking mode can comprise the step oflocking each of the vehicle opening devices. The first locking mode isadapted to the case of a user leaving the vehicle for a short period oftime.

It is envisaged that the second locking mode can comprise the steps oflocking each of the vehicle opening device and turning the vehicle mainswitch into an off state. The second locking mode is adapted to the caseof a user leaving the vehicle for a long period of time that is to say aperiod of time during which the battery may lose its power if it is notisolated.

The first locking action that sets the vehicle into the first lockingmode can consist of or comprise pressing once onto a push button locatedon the external side of the vehicle.

The second locking action that sets the vehicle into the first lockingmode can consist or comprise, for example, of pressing twice onto thepush button.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 diagrammatically illustrates a vehicle having a system capable ofimplementing a method according to the invention,

FIG. 2 to 8 illustrate each step of a method according to the inventionon a vehicle of FIG. 1,

FIGS. 9 and 10 are two flow charts illustrating the method of theinvention.

DETAILED DESCRIPTION

FIG. 1 depicts an industrial vehicle 1 of the truck type. A technicalfeature of specific interest for the present invention is a vehicle mainswitch 2. A main switch 2 is an on-off switch which is locatedimmediately downstream of a vehicle battery and therefore can isolatethe battery from the vehicle electric circuit.

The present invention concerns a vehicle passive keyless entry systemwhich can include a passive portable identification unit 3 and anonboard control unit 4.

The portable identification unit 3 can be, for example, a card which canbe easily carried by a user, for example, in a pocket or a bag. Thepassive portable identification unit 3 authenticates the identity of theuser. In other words, for security reasons, the access to a vehicle mustbe granted to a legitimate user i.e. a user that carries a portableidentification unit 3 suitable to gain access to a certain vehicle.

Authentication can rely on a bidirectional communication between thepassive portable identification unit 3 and the onboard control unit 4.

Typically, the onboard control unit 4 can include an electronic controlunit ECU 5. The ECU 5 can suitably be comprised of a microprocessor withI/O interface, ROM and RAM.

In the onboard control unit 4 of the vehicle, the ECU 5 is associatedwith at least one vehicle door handle 6; more specifically the ECU 5 canbe linked to a detection sensor such as for example a capacitive circuitwhich can be embedded in the door handle 6 and is capable of detecting acontact of a user with said door handle 6. The ECU 5 is connected to atleast one vehicle door latch 7 and can order the unlocking or locking ofsaid vehicle door. As shown on FIG. 1, the ECU 5 is also linked to oneor more low frequency antennas 9 which are capable of emitting a lowfrequency radio signal in an area of a few meters around the vehicle.Typically, there are as many antennas 9 as there are doors in thevehicle. The ECU 5 is also suitably connected to the vehicle main switch2, that is to say the ECU 5 can control the on or off state of the mainswitch 2.

It should also be noted that, the vehicle can be equipped with a pushbutton 10 and a capacitive sensor which conveniently can be located nextto the vehicle door handle 6. The push button 10 is also suitablyconnected to the ECU 5. The communication between the ECU 5 and eachunit can be suitably achieved through individual wire communication ormultiplexed communication.

The passive portable identification unit 3 can include a low frequencyreceiver typically in a range from 125 kHz to 13.6 MHz and a highfrequency transmitter typically in a range from 315 MHz to 900 MHz. Asthe passive portable identification unit 3 carries a transmitter, itneeds to be powered by a battery. The passive portable identificationunit 3 can be, for example, the size of credit card which is easy tocarry.

When a user wants to gain entry to a vehicle 1 which is in a lockedstate, the system can operate within the following unlocking sequencewith reference to the appended drawings.

First of all, it is assumed that the user carries a passive portableidentification unit 3. At a step 100, the user approaches the vehicleand lifts or pulls the door handle 6; by doing so, a signal istransmitted from the door handle 6 to the ECU 5 indicating an intentionto enter the vehicle. This step is illustrated on FIG. 2.

At this stage (step 200 of FIG. 9), the system has to perform anauthentication operation on the user.

As this is shown on FIG. 2, the ECU 5 can transmit a signal to the lowfrequency antennas 9. Typically, to authenticate the user, the ECU 5sends a random challenge to the passive portable identification unit 3.The passive portable identification unit 3 encrypts this value and sendit back to the vehicle as illustrated on FIG. 3. The ECU 5 performs asimilar encryption and compares the value received from the passiveportable identification unit 3 and the value calculated at the ECU 5; ifthe value matches the values calculated at the ECU 5, the user issuccessfully authenticated and the unlocking sequence continues.

At a step 300, the ECU 5 can transmit a signal to mechanically unlockthe door latch 7; thereby the ECU 5 authorizes the user to gain entry tothe vehicle. At step 400, the ECU 5 checks the state of the main switch2. If the main switch 2 is in an off state, a signal is transmitted tothe ECU 5 to close said main switch 2.

At this stage, the user can enter the vehicle 1 and the vehicle 1 is ina configuration whereby the vehicle can be started. A passive startprocedure can be carried out whereby the user who is at the wheel of thevehicle undergoes a further authentication procedure whereby it iscontrolled that the user does carry a suitable passive portable unit 3and can start the vehicle by simply pushing a button on the dash board.

Now, if the user intends to leave the vehicle 1, two vehicle lockingmodes can be activated upon a specific action of the user. Each vehiclelocking mode corresponds to a specific use of the vehicle.

The vehicle user can activate a first locking mode which in most casescorresponds to a short term vehicle standstill.

At step 600, the vehicle user leaves the vehicle and closes a vehicledoor; a door state sensor can inform the ECU 5 that the door is closed.

The vehicle user can exert a first action which can be, for example, asingle action on the push button 10. This first action is represented onFIG. 5 by a single arrow pointing to the push button 10.

An authentication sequence represented by step 700 of FIG. 9 similar tothe authentication action described above is then carried out to ensurethat the user is authorised to perform such an action.

The vehicle 1 can also be configured into the first locking mode by theuser walking away from the vehicle 1. In this case, the event thattriggers the vehicle being set in the first locking mode is the userwalking out of the field of the antenna 9.

At step 800, the vehicle doors are locked. FIG. 6 depicts the lockingsignal transmitted to the door latch 7. The fact that the vehicle is inthis first locking mode step can be backed by a visual signal such asfor example a brief flash of light and/or a sonorous signal such as forexample a brief hoot, thereby confirming to the user that the vehicle islocked according to the first locking mode.

Alternatively, as represented by step 900, the vehicle user can activatea second locking mode which in most cases corresponds to a long termvehicle standstill. In this second locking mode, the vehicle user exertsa second action which can be, for example, a double action on the pushbutton 10. FIG. 7 shows two arrows pointing to the push button 10. Thesecond action could comprise a long pushing action on the push button10.

To be taken into account by the onboard control unit 4, this input onthe vehicle has to be carried out by a user who is in possession of avalid passive portable identification unit 3. The authentication isaccomplished through the same bidirectional radio frequency exchange asdescribed above.

Once the user through the portable identification unit 3 that he or sheis carrying is authenticated, and the onboard control unit 4 hascompleted the authentication step, the ECU 5 transmits a locking orderto each of the vehicle opening devices such as the vehicle doors and/orsunroof and/or gate.

The ECU 5 also transmits a signal to the main switch 2 to put the mainswitch 2 in an off state as shown an FIG. 8. In this configuration, thevehicle can withstand a long term standstill as the vehicle battery isisolated. The fact that the vehicle is in this second locking mode stepcan be backed by a visual signal such as, for example, a long or adouble flash of light

and/or a sonorous signal such as, for example, a long or a double hoot.Thereby, the user has a further confirmation that the vehicle is lockedaccording to the second locking mode.

It can be envisaged to provide the vehicle with two push buttonslocated, for example, next to the vehicle door handle 6; each pushbutton which could be of a specific colour can set the vehicle in onethe locking mode.

The invention is not limited to the illustrative embodiments describedabove and shown in the drawings, but can be varied within the scope ofthe following patent claims.

1. A keyless entry and exit method for a vehicle which includes vehiclemain switch, wherein the method comprises (i) a vehicle unlockingsequence which comprises the steps of passively authenticating a vehicleuser, granting the authenticated vehicle user access to the vehicle andsetting the vehicle main switch into an on-state, (ii) a vehicle lockingsequence which comprises the steps of passively authenticating thevehicle user, configuring the vehicle, upon a first action from theauthenticated vehicle user, into a first locking mode whereby access tothe vehicle is denied to a non authenticated user, or configuring thevehicle, upon a second action from the authenticated vehicle user, intoa second locking mode whereby access to the vehicle is denied to a nonauthenticated user and the vehicle main switch is set into an off-state.2. The method according to claim 1, wherein user authentication is basedon bidirectional communication between a portable identification unitand an onboard control unit which is connected to vehicle locking meansand to the vehicle main switch.
 3. The method according to claim 1,wherein the first locking mode comprises the step of locking each of thevehicle opening devices.
 4. The method according to claim 1, wherein thesecond locking mode comprises the steps of locking each of the vehicleopening device and turning the vehicle main switch into an off state. 5.The method according to claim 1, wherein the first locking actioncomprises pressing once onto a push button located on the external sideof the vehicle.
 6. The method according to claim 1, wherein the secondlocking action comprises pressing twice onto the push button.